1. Field of the Invention
The present invention relates to a sheet feeding apparatus, and an image processing apparatus including this sheet feeding apparatus.
2. Description of the Related Art
Hitherto, an original feeding apparatus used in a scanner, copying machine, or the like, includes leading end regulating means for regulating leading ends of originals stacked up in an original stock unit, and a pickup roller for picking up and conveying stacked originals. The original feeding apparatus further includes a separating apparatus for separating and conveying the plural picked up and conveyed originals by one sheet each. The leading end regulating means is disposed between the pickup roller and the separating apparatus. The leading end regulating means prevents the leading end of an original from being pushed into the separating apparatus when the user stacks up a pile of originals on the original stock unit. The leading end regulating means also functions to align the leading ends of originals set by the user in the original stock unit. The pickup roller is movable to a position away from the stacking space so as not to hinder the user from stacking up the originals in the original stock unit.
Originals stacked up in the original stock unit are released from regulation of original leading ends of the original when the leading end regulating means is moved away. Then, the pickup roller descends to the top of the stacked originals and presses the originals from above. By the pickup roller, the originals are picked up and conveyed toward the separating apparatus. Driving means for moving the leading end regulating means, and driving means for raising or lowering the pickup roller, are individually provided. Or, for moving the leading end regulating means, and for raising or lowering the pickup roller, individual drive mechanisms using clutches and cams are respectively provided. Besides, as disclosed in Japanese Patent Application Laid-Open (JP-A) No. 8-310668, No. 2003-40475, and Japanese Patent Publication No. 3335973, by making use of lifting and lowering motion of the pickup roller, it is proposed to regulate the swing or the release of the regulation of the leading end regulating means.